The present invention generally relates to beamforming in ultrasound imaging systems, and in particular to a system and method for interfacing an ultrasound transducer with a computing device that performs beamforming processing.
Ultrasound diagnostic technology generally relates to imaging of biological tissue by transmitting ultrasonic waves into tissue of a body being imaged, and receiving and processing ultrasonic wave echoes reflected from the tissue. An ultrasonic imaging system typically includes a transducer array provided within a probe, a beamformer and a display/user interface subsystem. The transducer array couples the acoustic energy into and out of the body, and converts the received waves into electrical signals ready for processing. The display subsystem processes and displays received signals. The user interface provides means for allowing a user to enter commands for controlling components of the system. The beamformer includes a transmit beamformer which controls operation of the transducer array for forming the transmitted acoustic energy into a directed beam in the body being imaged, and a receive beamformer for processing the received echoes for forming lines of data ready for processing by the display subsystem.
The beamformer has been implemented in a wide variety of technologies. For example, initially receive beamformers were implemented in analog electronics for performing fundamental delay and sum operations. As it became cost effective to do so beamformer design migrated to digital technology, in which the received RF signals were converted to digital format by A/D converters. The high-speed digital data was subsequently processed in dedicated VLSI devices.
With the evolving development of digital technologies and personal computers, portions of the display/user interface subsystem and the beamformer functions have been implemented directly in a computing device such as a personal computer (PC). The ability to upgrade PC hardware while maintaining software compatibility over generations of hardware upgrades is one of the advantages achieved by incorporation of the beamformer into the PC, in addition to integration with the display/user interface subsystem. However, the incorporation of the beamformer into the PC is limited due to the large data bandwidth, for example 128 channels of high speed RF data, processed by the beamformer.
Personal computers have architectures characterized by one or more central processors or microprocessors. These processors communicate to external devices by means of input/output (I/O) interface cards, which provide for the unique requirements of differing peripheral devices such as monitors, keyboards, etc. These peripheral devices are characterized by low data bandwidth relative to the needs of an ultrasound beamformer. Beamformer incorporation into the PC has required processing of the high speed RF data by external hardware devices for performing mathematical operations and convergence of the data into a narrow data stream provided to the PC via an I/O slot. However, the external hardware is expensive, requires custom design and manufacture for individual applications, and is limited in its ability to expand and adapt.
A beamformer for an ultrasound imaging system is provided, the ultrasound imaging system having a probe having a transducer array for transmitting and receiving analog signals, and a personal computer. The beamformer includes a beamformer software application module configured for execution by the computing device for performing at least partial beamforming processing on digital data transmitted between the transducer array and the computing device, and means for exchanging signals and data between the transducer array and the computing device and performing at least one of A/D and D/A conversions on the exchanged signals and data. In the preferred embodiment, the beamformer further includes a module integrated within architecture of the computing device, wherein the integrated module is preferably Random Access Memory (RAM) included in storage means of the computing device. The means for exchanging signals includes an interface module coupled between the transducer array and the computing device for performing the conversions. A method is further provided for performing a transmit beamforming process in an ultrasound system having a computing device and a probe including a transducer array, the method including the steps of performing transmit beamforming processing in the computing device in accordance with transmit settings to generate digital transmit data, storing the digital transmit in the data storage memory, retrieving the digital transmit data from the storage memory, converting the digital transmit data to analog transmit signals, and transmitting the analog transmit signals to the transducer array. A method is further provided for performing a receive beamforming process in an ultrasound system having a computing device including storage memory, a interface module and a probe including a transducer array, the method including the steps of receiving analog signals from the transducer array, converting the analog signals to digital data, storing the digital data in the storage memory, retrieving the digital data from the storage memory, and performing receive beamforming operations on the digital data by the computing device.